Furnace grate



May31938- F. HELMlcK 2,116,024

RRRRRRRRRR TE F. HELMICK FURNACE GRATEv May 3, 1938.

Filed Aug. 26, 193e 4 Sheets-Sheet 2 IIIIIIIL! umm! mnu@ um@ mmm! mlm r Mill? ALNH!! IAIIIIIIIIII ,lllllllllll UNIL! ilmnm! umm May 3, 1938. F HELMICK 2,116,024

FURNACE GRATE Filed Aug. 26, 1936 4 Sheets-Sheet 3 0mm www Many 3, 1938. F HELMlCK 2,116,024

FURNACE GRATE Filed Aug. 26, 1936 A Sheets-Sheet 4 Patented May 3, 1938 .UNITED STATES PATENT OFFICE FURNAE GRA'IE Frederic Helmick, Fairmont, W. Va. Application August 26, 1936, Serial No. 98,024 9 claims. (c1. 12e-163) This invention relates to certain new and useful improvementsingrate 1bar constructions, especially` designed ffor usein furnaces having automatic stokers and as illustrated in the drawings show a plurality ofgrate bars assembled in an extension frame of an underfeed Stoker for boiler furnaces.

Another object of my invention is tov provide a plurality of grate bars when assembled with maximum Zig-zag-air spaces between and through the grate bars from the upper to the lower end of the stepped portion of the grate bars.

A still further object of the invention is to increase the air `passages between and through the assembled grate bars to increase the distribution of air, l,which is accomplished by having air passages from top to bottom of the stepped portion of the grate surface of a zig-zag formation.

A still further object ofthe invention is to provide the bars with,V strengthening flanges or ribs whiclrrform shelves that retard the sifting of the flnefashes through the air spaces between the assembled grate bars into'the air channel whereby any ashes that sift through will be blown back from the wind box throughthe air outlets into the combustion chamber of the furnace.

`A still `further object of the invention is to provide a. grate bar so constructed that when a plurality of these bars are assembled that the air passingthrough the air outlets will contact more forcibly with those portions of the grate bar exposed tothe greatest heat, thereby increasing the life of the grate bar.

AOther and further objects and advantages of the invention will be hereinafter set forth and the novel features thereof defined by the appended claims. c

Inlthe drawings,

Figure 1 is aperspective view of a plurality of grate bars constructed in accordance with my invention assembled on an extension frame, the bars being broken away to sho-w the construction of the frame;

Figure 2 is a front elevation of a grate bar assembly constructed in accordance with my invention, partly broken away;

Figure 3 is a top plan View, partly broken away;

Figure 4 is a vertical section through the extension frame showing the grate bar in elevation;

Figure 5 is an inverted plan view of one of the grate bars;

\ Figure 6 is a longitudinal section through one of the bars; and y l Figure? is a section taken on line 'I-1 of Figure 6.

4In the embodiment of my invention as herein shown, Ishow a plurality of interlocking hollow Y be used in underfeed stokers for boilerfurnaces. The grate bars A are constructed exactly alike with the exception of the end bars A and the description of one of the intermediate bars will be suilcient for all. These bars are assembled in an extension frame to form a grate with its upper face in downwardly trending step formation to provide a plurality of air outlets from the wind boxes extending at an angle to the longitudinal center of the respective bars tomore equally distribute the air into the fuel bed overlying the grate, thereby increasing the combustion.

The hollow grate bars A have a body portion which is substantially inverted U-shape in cross section and zig-Zagin formation having a horizontally disposed flat portion I at its upper end, the lower end being stepped to form tread portions 2 and riser portions 3, `the lower riser portion I being provided with spaced air outlets 5 formed by a web 6 which extends rearwardly and downwardly as shown,` for deflecting the air through these' outlets. One side wall of` each step 4 is provided with a lateral and rearwardly extendingflange 'I which extends between flanges B and 9 formed on the opposite side wall of the adjacent bar, the flange 9 being an extension of the tread IU and having a rearwardly and downwardly extending portion I I.

The riser of each step is cut out between the legs of the inverted U shaped body to forman air outlet I2 extending at an angle to the longitudinal center of the bar, a web I3 being disposed between the legs of the inverted U portion of the body of the bar which extends rearwardly and downwardly to deflect the air from the wind box through the outlet andagainst the tread. One edgeof the tread 2 of-each step is extended laterally as shown at I4 and then rearwardly and downwardly at an angle to the tread to form a lateral flange which extends between the flanges of the adjacent bar so that when a plurality of ,these grate bars are assembled, the flanges along one side of the grate bar extend between the flanges of the; adjacent grate bars to provide air outlets I8 from the wind box to more equally distribute the air to the grate and to provide means for blowing back any ashes sifting between the'respectivegrate bars. It will be noted that when a plurality of these grate bars are assembled that the air outlets formed in the riser of one step extend obliquely in one direction and in the next step obliquely in the-opposite direction.

The outside grate bars A have their inner edges corresponding in shape and ldesign with the adjacent edge of the adjacent grate bar.` The outside edges of the outside bars A are formed to conform with the flat sides of the frame B and are provided lwith flanges A2.

*The flatv portion I of the grate barshave. overhanging flanges I6 along one edge, the `upper faces the under sides of the tread. Theunder side of the beveled portion of the tread is in a plane parallel with the beveled portionftoI deflect the air` downwardly on the adjacent tread throughthe Y fuel thereon.

The grate bars are provided with lugs` I9 embracing transverse bars 2U of the frame B and with notches 2l into which extendl the upper ends oivertically disposed bars 22 of the frame B. 'Ihe outside bars A are secured torapertured threaded lugs 23 by bolts 24, the particular manner of mounting these barsV in an extension frame of an underfeed stoker can be changed without departing from the spirit of my invention. v

The under side of the lower ends of the grate bars are cut to provideshoulders 25 which rest on shoulder 26 formed on the lower end of the frame B and when a plurality of. these grate bars are assembled on an extension frame, a grate is produced which is very strong and durable and in which the air from the wind box is equally distributed to the combustion chamber.

Inconstructing a grate in accordance with my invention, each of the intermediatehollow grate bars is of a stepped longitudinal zig-zag formation with ay body portionsubstantially inverted U shape in cross section with alternately extending4 flanges fromthe treads of the steps as it will benoted that thetread ofthe lower step is extended to the left to form a flange and the tread of the next step extended tothe right to form a flange, this being carried out throughout the length of the grate bar whereby I notonly provide outlet passages extending through each grate bar but toeach side, each `outlet passage having a deliector. for deecting the Yair so as to more equally distribute they air to the-bed of fuel in the grate.

From the foregoing description it will ybe seen that Ihave produced a hollow grate bar zig-zag in formationwith a body portion substantially inverted U shape in cross section having a steppedY portion in which the risers of the steps are providedA with air outlets having deflectors forV deflecting the air against the under side of the tread and when a plurality of these bars are assembled with their flanges interlocked, additional air outlets are formed between the respective grate bars having deectors formed by the rearwardlyextending portion of the anges for deflecting the air against the lateral extending portions of the treads whereby I am able to more equally distribute the air from the wind box to cause the same to be forced against those portions of the grate bar which are subjected to the greatest amount of heat and at the same time I am able to collect any line ashes sifting through ,the spaces between the grate bars so that vthese ashes will be blown back -tothe combustion chamber.

What I claimy is:

1. Agratelcomposed of a plurality of interlock-V ing hollow grate bars, each bar having a stepped longitudinal zig-zag formationand, an open bottom, the riser of each step-being provided with an air outlet.I

l wardly in the opposite direction to provide flanges for spacing the bars apart to provide additional air outlets.

3. A grate bar formed of a plurality of interlocking hollow grate bars, each grate bar having astepped zig-zag longitudinal formation and an open bottom, the riser of each step being provided with an air outlet, the tread of one step being extended outwardly in one direction and the tread of the adjacent step being extended outwardly in the opposite directionto provide flangesfor spacing the bars apart to provide additional air outlets, the bars being provided withl deflecting portions for delecting the air through the outlet. openings. l

. 4. A grate bar having a stepped zig-zag longitudinal formation, the riser of each step being provided with an outletthe outlet of. one tread extending atan angle to the outlet ofthe adjacent tread. f

5. A gratecomprising a plurality of interlocked hollowVv grate bars, the intermediatey grate bars having a stepped zig-zag longitudinal formation and an open bottom, the alternate treads of said steps being extended laterally and rearwardly to provide flanges for spacing the risers of said steps apart to provide air out1ets,the riser of each step being provided with an air outlet.

6. A grate of the kind described composed of a plurality of. hollow grate bars arranged within a frame, each grate bar having a longitudinal` step zig-zag in formation and an open bottom, the treads of each step being. provided with lateral flanges for spacing said grate bars apart to provide outlets between the respective grate bars, the riser of each step being provided with an air outlet.

7. A grate of the kind described adapted to be' arranged over a wind box formed of a plurality of, hollow grate bars, each grate bar having a longitudinal stepped zig-zag formation and an open bottom) the treads of said steps being provided with lateral flanges for spacing said barsapart to provide air outlets, the riser of said steps being provided with air outlets, the air outlets of the riser extending at an angle to one another.

8. A grate of the kind described adapted to be arranged over a wind box formed of a plurality of, hollow grate bars, each grate bar having a longitudinal stepped zig-zag formation and an open bottom, the treads of said steps being provided with lateral vllanges for spacing said bars apart to provide air outlets, the risers of said steps being provided with air outlets, the air outlets of the risers extending at an angle to one another, said bars being provided with rearwardly and downwardly extending portions to form deflectors for deflecting the air against the under side of the treads of said steps.

9. A grate formed of a plurality of. closely assembled hollow grate bars having a longitudinal stepped formation and an open bottom, the riser of each step being provided with an air outlet, the outlet of one riser extending at an angle to the outlet of the adjacent riser of said bar.

FREDERIC HELIVDCK. 

